Automatic motor-starting resistance.



PATENTED NOV. 28, 1905.

R. SCOTT. C MUTDR STARTING RESISTANCE. APPLICATION FILED JUNE 15, 1904.

AUTOMATI I nven tor Wi messes Httomegs UNITED STATES PATENT OFFICE.

RALPH SGOTTQOF WILKESBARRE, PENNSYLVANIA; AUTOMATIC moron-swarmsnEsisTA'N'cE.

Specification of Letters Patent.

Patented Nov. 28, icon.

' Application filed June 15, 1904. Serial No, 212,744.

To all wwom/ may concern:

Be it known thatI, RALPH SCOTT, a citizen of the United States, residingat Nilkesbarre, inthe county of Luzerne and State of Pennsylvania, haveinvented a new and useful Automatic Motor-Starting Resistance, of whichthe. following is a specification.

This invention relates to improvements in automatic motor-startingresistances, and has for its principal object to construct an automaticstarting resistance of the most simple and eflicient character andonefwhich may be readily adjusted in order' to cut out the resistings,and particularly pointed out in the aption.

. invention.

pended claims, it being understood that vari ous changes in the'form,proportions, size, and minor details of the structure may be madewithout departing from the spirit or sacrificing any of the advantagesofthe inven- In the accompanying drawings, Figure 1- is a sectionalelevation of an automatic starting resistance constructed in accordancewith the Fig. 2 is an elevation, partly in section, illustrating aslight modification of the invention. i

The device forming the subject of the present invention is one of thatgeneral class in whichwhen the motor-circuit is completed a resistanceis cut in in order to prevent sudden starting of the motor, and suchresistance. is

gradually cut outuntil it is finally eliminated,

at which time the motor will have attained full speed.

The various working parts of the apparatus are mounted on a suitableslab or base 1, formed of non-conducting materialioandprovided'withopenings 26 for the passage of securing-screws or other fasteningdevices. At

a point near the top of the base-plate isse-' cured a bracket 5, held inposition by screws orsimilar fastenings 3, and this bracket supports adash-pot 2, formed of any suitable ma- -terial,the dash-pot beingsecured to the bracket .suitable manner to the slab or base 1.

resistance-bar 8.

by a fastening means-such, for instance, as a pin 4. In the upper end ofthe dash-pot is an air-opening 6, preferably tapered to form a valveseat for the reception of a valve 6', which may be in the form ofasphere. Under pressure of air in the dash-pot the valve will be forcedto its seat and close the opening 6; but

when pressure is reduced the valve falls from; 1

its seat and allows air to flow into the dash-p ot. Within the dash-potis placed a plunger 7, which may be formed of graphite'or other suitablematerial, and depending from thev plunger is a resistance-bar 8 formedof any suitable material, such as carbon or carbon compounds, the lowerend of the resistancev cessively cutting out portionsof the resist ance,these bars from top to bottombeing successively brought into engagementwithcarbon or other contact-blocks 20, carried by asupporting-bracket-i'l, that normally comes into engagement with thecontact-rings 23 by screws 9. to an inverted-cup-sha-ped casing 15,

formed of soft iron, said casing forming a housing orclosure for asolenoid-coil 11 which is insulated'from the housing by a ring orcylinder 21, that extends comp'letely'around the solenoid-coil. Thesolenoid and the insulating material are held in place by a spool.magnetic screws 22, and the solenoid and its casingas a wholearerigidlysecure'd in any Fitting within the solenoid is an iron core12, atthe lower'end of which is a collar .or flange 25, extending outward andof a diameter equal at least to the diameter of the casing or hous- 1ing 15 in order to render the magnetic field-- of the solenoid moreeffective and to retain the core in elevated position with a minimumexpenditure of energy. Secured to the core and moving longitudinallywith said core is'a rod 14, formed of brass or other non-magneticmaterial .and forming a support for the an opening in aguiding-bracktlS, that is secured to the lower portion of theslab or andfrom thence to the motor-field.

screw 31, and the enrged shoulder at the top of the reduced poron of therod serves to limit the upward movementv of the core by engaging againstarid bracket.

Returning now to the dash-pot, 36 desig rates a nipple in communicationwith the dash- ;pot and having a valve-seat 37 and a port 35 leading tothe outer-air. The nipple is threaded for the reception o" aneedle-valve 38, profl/lili :nilled or knurled z nob 33, by which revalve may be adjusted inorder to control the discharge of air from thedash-pot.

At one side of "he slab are binding-posts M M, to which the mainline-wires are conected. {in the opposite side. of the base areriding-posts M, A, and F. One of the linewires leads from binding-post Mto bindingpost M and from thence to the motor. From f." 1i! iing post Mleads a wire 40 to the sonoid-core, and from thence to bindin -postAsceond wire s1 leads from the binding-post M to the bracket B, which isconnected, through therod 141:, to the resistance-rod 8 and from thenceto contacts 20, bracket 17 and springs 19 to the housing or casing 15and by wire 42 to the binding-post A, from whence it passes to themotorermature.

When the circuit is closed, the solenoid is energized and graduallyraises the core 12, the speed at which the core is elevated beingdependent on the extent to which the valve 38 aided its outer e opened,and by altering the size of the pasirom the dash pot the speed may beincreased or diminished in accordance with circnmstances. As the core iselevated the successive contact-rings :23 are brought into en-.

gagement with the contact-blocks 20, and as these are disposed atdiametrically opposite points good contact of one or both is at alltimes assured. On the completion of the upward movement, which mayoccupy any predetermined length of time, the flange 25 of the'spoolcomes into engagement with the nonmagnetic screws 22 and is heldslightly away from the soft-iron casing or housing 15, so that when thecircuit is broken the core may fall and will not be held by residualmagnetism, as will'be the case if the flange comes into directcontactwith the casing or housing.

in Fig. Qis illustrated aslight modification oi the invention, theresistance-bar 8 in this instance being in the form of flat plates orslabs provided with a plurality of contact-buttons 23, and at the top ofeach of the plates is a metallic contact-strip 23". Theresistance-plates in this instance are stationary, and

the contact-blocks 20 are carried by posts 17,

4 projecting from a central block 29, that is seance is gradually cutout until the plates 23"- are reached, at which time the resistance iswholly eliminated. The circuit in this instance. may be traced frombinding-post N through the solenoid to one of the end plates 23, thencethrough the rcsistance'to block 20' and across to the opposite block 20,thence through resistance to plate 23", and finally to binding-post A.The resistance in this case is intended to be in series with thearmature of a motor. In both cases the period of time required forcutting out the resistance may be adjusted in accordance withrequirements, and when the circuit is broken the weight of the core 12and the associated parts will cause the contact-buttons to again engagewith the last contact of the resistance-bar, so that all" resistance isheld in the circuit in readiness for another operation.

Having thus described the invention, what is claimed is- 1. In a deviceof the class specified, a resistance-bar, a plurality of contact memberson said resistance-bar, a contact member for engaging the contacts ofthe resistance-bar, said contact member and resistance-bar constitutingtwo members of a circuit-controlling device, one

' of which is movable with respect to the other,

a solenoid having an iron casing, a movable core connected to themovable member and having an enlarged flange that is attracted by thecasing when the solenoid is energizedI'a non-magnetic spacing meanspreventing contact between the flange and the casing, and a dash-pot forcontrolling the speed of movement of said core. I

2. In a device of the class specified, a solenoid, a movable core. aresistance-bar carried.

by the core, a plurality of contact members on said resistance-bar,contact members carried by the solenoid for. engagement with thecontacts of the resistance-bar, a plunger secured to the resistance bar,and a dash-pot into which said plunger extends.

3. In a device of the class specified, a solen oid, a solenoid-core, aresistance-bar supported by the core, a plurality of contact-rings onsaid resistance-bar, a pair of diametrically-on posed contacts carriedby the solenoid for engagement with the contacts of the resistancc bar,a plunger secured to the resistance-bar, and a dash-pot into which S21id plunger extends.

4. In a device of the class specified, a solenoid, a solenoid-core, a,resistance-bar secured to the core, a plurality of spaced contact-ringscarried by the resistance-bar, a pair of springheld contact-blockssupported by the solenoid and adapted to engage the contact-rings of theresistance-bar, a plunger secured to the resistance-bar, and a dash-potinto which said plunger extends.

5. In a device of the class specified, a solening, a. resistaucehzu:

' an enlarged fian e gage the contacts 0;?

seilic red seen:

oidhavingazso'ft i 1a cesinp nrhonsing, a core having an enlarg flangethe: is attracted by the casing or housing; when the scleneid isenergized'anon-in net r m? means pre- Venting cn'ntzics n en n s end thescppei ued by the cere end of spaced contacts; a conce ing and adaptedto en the re istance-bar, and means for retarding movement of the scicnbid-core In a having a plnrelxi tact carried by tl device of the classspecified, a s0ien- 0351, an inverted --cn.p like easing or housing forsaid SOlGDOlCl, a men-magnesia: speel for the s0- -len0id-winding, saidspool having an enlarged flange, enon-magneticrneans for securing saidflange to the'casing insulating material surrounding the scleneid iinding, a core having adapted '50 en n e the seent direct nmcle bccuringmeans a tween the core ts the ccre, guidingind the casing, 21-2116"nncedmr; a cylindrical deslvpot into which said i plunger enters, avalved air-inlet for the dashl pet, a nipple projecting from thedash-pot l and provided with an air-outlet port, anda l needle-valvecarried. by the nipple and serw l ing to adjust the effective area ofsaid outlet- 1 port.

' in testimony that I claim the foregoing as l my own I have heretoniiixed my signature in 1 the presence of two witnesses.

l l I l l l EJBJLPH SCOTT.

Vi 'itnesses;

FRANK Seem, Tees. M. HERBERT.

